Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Chicago Department of Aviation spokeswoman Karen Pride says there was "a pressurization problem" on American Airlines Flight 2363, which landed about 10:30 a.m. Sunday. The flight had taken off from Chicago and returned there.

Pride didn't have further details.

An American Airlines spokesman didn't immediately respond to a request for comment.

The airline's Web site says the flight was headed from O'Hare to the Yampa Valley Regional Airport in Colorado. It arrived at its destination after 1 p.m. — about two hours later than scheduled.